The invention relates to providing common mode noise filtering for integrated circuits.
Where noise that exists in an integrated circuit (IC), for example on ground and power lines within an IC, is coupled to the environment, this can result in electromagnetic interference (EMI) problems.
For example, where there are a large number of outputs (e.g., a large number of serializer/deserializers (SerDes)) in an IC that are clocked from a common clock reference source, this can contribute significantly to the noise level on ground and power within the IC. Then, where all output drivers of the SerDes are active, the ground noise can end up being coupled to the environment through low common mode impedance differential lines to an extent that can cause significant EMI problems.
The present invention seeks at least to mitigate such problems.